The common indoor/outdoor plant most people know as geranium is, botanically, Pelargonium. Considered here are true geraniums, which are mostly hardy plants. Many types bloom over a long period, bearing flowers that are attractive though not always as showy as those of pelargoniums. Carried singly or in few-flowered clusters, blossoms have five overlapping petals that look alike. (Pelargonium flowers also have five petals, but two point in one direction, while the other three point in the opposite direction.) Colors include blue, purple, magenta, and bluish rose; some are pure pink or white. Beak-like fruit that follows the flowers accounts for the common name “cranesbill.” Leaves are roundish or kidney shaped, lobed or deeply cut; plants may be upright or trailing.
Good in rock gardens, perennial borders; some are useful as small- or large-scale ground covers. A few shrubby species are good for holding slopes. Best climates for most geraniums are cool- and mild-summer regions, where plants can grow in full sun or light shade. In hot-summer areas, give afternoon shade. South African species are less cold hardy but more tolerant of heat, afternoon sun. All species appreciate moist,well-drained soil.
Some geraniums benefit from being cut back after flowering or in the fall; these are noted in text. Clumps of most types can be left in place for many years before they decline due to crowding; at that point, divide in early spring. Increase by transplanting rooted portions from a clump’s edge; or take cuttings. Many produce lots of seedlings, and some can become naturalized pests.
Dramatic native of Madeira likes moist conditions, shade. Largest of all geraniumleaves (to 2 ft. long)—overlapping,glossy, deeply divided,shaped like giant snowflakes. Reddish brown leafstalks helpbuttress the 3–4-ft. “trunk” supporting hundreds of densely packed, fuzzy buds and magenta-eyed deep pink blossoms to 1 1/2 in. wide. Blooms early spring through midsummer. Biennial or short-lived perennial; dies after blooming but spawns many seedlings.
Highly variable in size and form. Among most widely distributed is ‘East Grampians‘, a low...
Briefly deciduous. To 40–60 ft. tall; pyramidal in youth but more spreading (toabout 30 ft.) in maturi...
Thought to be a hybrid involving Grevillea x gaudichaudii. Like that parent, it is low and sp...